4H-3,1-Benzoxazine derivatives

ABSTRACT

4H-3,1-Benzoxazine derivatives of the formula ##STR1## where R 1 , R 2  and Y have the meanings given in the specification, and their use for controlling unwanted plant growth in numerous crops, such as cereals, Indian corn, soybeans and cotton.

The present invention relates to 4H-3,1-benzoxazine derivatives, herbicides containing these compounds as active ingredients, and a process for controlling undesired plant growth with these compounds.

Substituted 4H-3,1-benzoxazin-4-ones are known as intermediates for the synthesis of drugs (German Laid-Open Applications DOS Nos. 1,670,375 and 3,556,590) and as herbicidal active ingredients; in particular, 4H-3,1-benzoxazin-4-ones which carry an unsubstituted or substituted phenyl radical in the 2-position are herbicidally active (Belgian Pat. No. 648,259 and U.S. Pat. Nos. 3,970,652 and 3,914,121). The known compounds are well tolerated by a number of crops, eg. species of grain, rice, Indian corn and sorghum. Their shortcomings reside in a narrow spectrum of action on broad-leaved weeds. Furthermore, even in the case of plants which these benzoxazines control effectively, relatively large amounts per unit area must be used.

We have found that 4H-3,1-benzoxazine derivatives of the formula I ##STR2## where Y is oxygen or sulfur,

R¹ is hydrogen, halogen, nitro, alkyl, haloalkyl, haloalkoxy or haloalkylmercapto, each of 1 to 4 carbon atoms, cyano, thiocyano, CO₂ R³, ##STR3## Y'R⁴, SOR⁴, SO₂ R⁴, SO₂ OR⁴, ##STR4## or CO--R⁴, where R³ is alkyl or alkenyl of up to 4 carbon atoms,

R⁴ is alkyl of 1 to 4 carbon atoms,

R⁵ is hydrogen or alkyl of 1 to 4 carbon atoms,

Y' is oxygen or sulfur and

R² is a cycloaliphatic or bicycloaliphatic radical of 3 to 10 carbon atoms which is monosubstituted or polysubstituted by methyl, or is a pyrimidine, pyrazine, pyridazine, triazine, thiazole, isothiazole, pyrazole, imidazole, triazole, oxazole or isoxazole radical which is unsubstituted or is monosubstituted or polysubstituted by methyl and/or halogen, or is a furan, morpholine or pyridine radical which is monosubstituted or polysubstituted by methyl and/or halogen, and, if R¹ is hydrogen, R² may also be an m-substituted or p-substituted, or m- and p-substituted, aryl radical of the formula Ar(R⁶)_(n), where Ar is phenyl and R⁶ is alkylmercapto, haloalkoxy, haloalkylmercapto, alkylsulfinyl, haloalkylsulfinyl, alkylsulfonyl or haloalkylsulfonyl, each of 1 to 4 carbon atoms, ##STR5## alkoxycarbonyl, alkenyloxycarbonyl, alkylmercaptocarbonyl or alkenylmercaptocarbonyl, each with alkyl or alkenyl of 1 to 4 carbon atoms, NH--CO--NH--CH₃, NH--CO--N(CH₃)₂, ##STR6## formamido, alkoxycarbamyl, alkenyloxycarbamyl, alkylmercaptocarbamyl, alkenylmercaptocarbamyl, alkylmercaptodithiocarbamyl, alkenylmercaptodithiocarbamyl, alkylcarbamido, dialkylcarbamido, alkenylcarbamido, dialkenylcarbamido, alkylsulfamyl, dialkylsulfamyl, alkylsulfonamido or haloalkylsulfonamido, each with alkyl or alkenyl of 1 to 4 carbon atoms, or formyl, and n is 1 or 2, and if R¹ does not denote hydrogen or halogen. R⁶ may also denote hydrogen, halogen, cyano, thiocyano, nitro, haloalkyl of 1 to 4 carbon atoms or acyl of 2 to 5 carbon atoms, and if R¹ denotes fluorine or hydrogen and n is 2, R⁶ may also denote hydrogen, fluorine, chlorine, nitro or alkoxycarbonyl of 2 to 5 carbon atoms, and if R¹ denotes halogen and n is 1, R⁶ may also denote haloalkoxy, haloalkylmercapto or alkylsulfinyl, and if R¹ denotes hydrogen, R² may also be aralkyl substituted in the m-position or p-position or m- and p-position, by haloalkyl or haloalkoxy, each of 1 to 4 carbon atoms, are excellently tolerated by crop plants and exhibit a substantially more powerful herbicidal action than the benzoxazines hitherto disclosed.

In formula I, R¹ is, for example, hydrogen, fluorine, chlorine, bromine, iodine, nitro, methyl, ethyl, isopropyl, n-propyl, n-butyl, isobutyl, tert.-butyl, trichloromethyl, difluorochloromethyl, trifluoromethyl, difluoromethyl, 2,2,1,1-tetrafluoroethyl, trifluoromethoxy, hexafluoroisopropoxy, difluoromethylmercapto, trifluoromethylmercapto, a radical of the formula Y"CF₂ C(Z)₃, where Y" is oxygen or sulfur and each Z independently may be hydrogen, fluorine, chlorine, bromine or iodine, eg. 2,2,1,1-tetrafluoroethoxy, 1,1-difluoroethoxy, 2,2,1,1-tetrafluoroethylmercapto and 1,1-difluoroethylmercapto, cyano, thiocyano, CO₂ CH₃, CO₂ C₂ H₅, CO₂ --CH(CH₃)₂, CO₂ --CH₂ --CH═CH₂, CO--N(CH₃)₂, CO--N(C₂ H₅)₂, methoxy, ethoxy, n-butoxy, isobutoxy, methylthio, ethylthio, n-propylthio, sec.-butylthio, SOCH₃, SOC₂ H₅, SO₂ CH₃, SO₂ C₂ H₅, SO₂ C₃ H₇, SO₂ OCH₃, SO₂ OC₂ H₅, SO₂ OC₄ H₉, SO₂ --NHCH₃, SO₂ --N(CH₃)₂, SO₂ --N(C₂ H₅).sub. 2, formyl, acetyl and propionyl.

R² in formula I is, for example, cyclopentyl, cyclohexyl, α- , β- or γ-methylcyclopentyl, α- , β- or γ-methylcyclohexyl, 1,4-methano-bicyclo-(4,3)-nonane, 2-methyl-fur-3-yl, 3-methyl-fur-2-yl, 4-methyl-fur-2-yl, 5-methyl-fur-2-yl, 2-methyl-fur-4-yl, 3-methyl-fur-4-yl, 2,5-dimethyl-fur-4-yl, 4-methyl-pyrid-2-yl, 5-methyl-pyrid-2-yl, 2-methyl-pyrid-4-yl, 2-methyl-pyrid-5-yl, 3-chloro-pyrid-5-yl, 2-chloro-pyrid-4-yl, 2-chloro-pyrid-5-yl, pyrimidin-2-yl, -4-yl, -5-yl or -6-yl, 4-methylpyrimidin-2-yl, 4-chloropyrimidin-2-yl, pyridazin-3, -4-, -5- or -6-yl, imidazol-1-, -2-, -4- or -5-yl, 5-methylimidazol-2-yl, 2-methyl-imidazol-5-yl, oxazol-2-, -4- or -5-yl, 2-methyl-oxazol-5-yl, isoxazol-3-, -4- or -5-yl, 3-methyl-isoxazol-5-yl, 3-chloro-isoxazol-5-yl, 1,2,4-triazol-1-yl, 1,2,5-triazin-3-yl, 1,2,5-triazin-4-yl, 1,2,4-triazol-3-yl, 1,2,4-triazolyl-5-yl, α-pyrazinyl or aryl, especially phenyl which may be substituted by the following in the m-position, p-position or m- and p-position: methylmercapto, ethylmercapto, isopropylmercapto, chloromethoxy, fluoromethoxy, difluoromethoxy, difluorochloromethoxy, trifluoromethoxy, trichloromethoxy, 1,1,2,2-tetrafluoroethoxy, 1,1,2-trifluoro-2-chloroethoxy, 1,1,1-trifluoro-2-bromoethoxy, 1,1,2,3,3,3-hexafluoro-n-propyloxy, pentafluoroethoxy, hexafluoroisopropoxy, difluoromethylmercapto, trifluoromethylmercapto, pentafluoroethylmercapto, 1,1,2,2-tetrafluoroethylmercapto, trichloromethylmercapto, dichlorofluoromethylmercapto, trifluoromethylmercapto, CH₃ SO₂, C₂ H.sub. 5 SO₂, i--C₃ H₇ SO₂, ClCH₂ SO₂, F₂ CHSO₂, CF₂ SO₂, CF₃ CF₂ SO₂, ##STR7## CO₂ CH₃, CO₂ C₂ H₅, CO₂ --i--C₃ H₇, CO₂ --n--C₄ H₉, CO₂ --CH₂ CH═CH₂, CO--SCH₃, CO--SC₂ H₅, CO--S--i--C₃ H₇, CO--S--CH₂ --CH═CH₂, NH--CO--NHCH₃, NH--CO--N(CH₃)₂, ##STR8## NH--CHO, NH--COOCH₃, NH--COOC₂ H₅, NH--COO--i--C₃ H₇, NH--COO--sec--C₄ H₉, NH--COOCH₂ --CH═CH₂, NH--CO--SCH₃, NH--CO--SC₂ H₅, NH--CO--S--i--C₃ H₇, NH--CO--S--CH₂ --CH═CH₂, NH--CS--SCH₃, NH--CS--SC₂ H₅, NH--CS--S--i--C₃ H₇, NH--C--S--S--CH₂ --CH═CH₂, CO--NHCH₃, CO--NHC₂ H₅, CO--NH--i--C₃ H₇, CO--N--H--sec--C₄ H₉, CO--NH--CH₂ --CH═CH₂, CO--N(CH₃)₂, CO--N(C₂ H₅)₂, CO--N(i--C₃ H₇)₂, CO--N(CH₂ --CH═CH₂)₂, SO₂ --NHCH₃, SO₂ --NHC₂ H₅, SO₂ --NH(i--C₃ H₇), SO₂ --N(CH₃)₂ , SO₂ --N(C₂ H₅)₂, NH--SO₂ --CH₃, NH--SO₂ --C₂ H₅, NH--SO₂ --CF₃, NH--SO₂ --NHCH₃, NH--SO₂ --NHC₂ H₅, CHO, fluorine, chlorine, bromine, iodine, cyano, thiocyano, nitro, acetyl, propionyl, trifluoromethyl, difluorochloromethyl, difluoromethyl or 1,1,2,2-tetrafluoroethyl, or aralkyl, eg. benzyl, which may be substituted in the m-position or p-position or m- and p-position, for example by trifluoromethyl or trifluoromethoxy.

Preferred compounds of the formula I are those where R¹ is hydrogen, R² is substituted phenyl, R⁶ is haloalkoxy, haloalkylmercapto or alkylsulfinyl, each of 1 to 4 carbon atoms, and n is 1, or where R¹ is halogen, R² is substituted phenyl, R⁶ is haloalkoxy, haloalkylmercapto or alkylsulfinyl, each of 1 to 4 carbon atoms, and n is 1, those where R¹ is hydrogen, R² is substituted phenyl, R⁶ is halogen, haloalkoxy, haloalkylmercapto or alkylsulfinyl, each of 1 to 4 carbon atoms, and n is 2, or those where R¹ is fluorine, R² is unsubstituted or substituted phenyl, R⁶ is hydrogen or halogen and n is 2.

Further, we have found that benzoxazine derivatives of the formula I are obtained if an unsubstituted or substituted anthranilic acid of the formula II ##STR9## where R¹ and Y have the above meanings, is reacted with a twofold or even higher molar excess of a carboxylic acid halide of the formula III ##STR10## where R² has the above meanings and Hal is halogen, especially fluorine, chlorine or bromine, in an aromatic tertiary amine as the solvent, at from 10° to 60° C.

If 3-nitro-4-chloro-benzoyl chloride and anthanilic acid are used as starting materials, the course of the reaction may be represented by the following equation: ##STR11##

Advantageously, a twofold molar excess of the carboxylic acid halide of the formula III is run into a solution of the unsubstituted or substituted anthranilic acid of the formula II in from 5 to 25 moles of an aromatic amine per mole of anthranilic acid, at from 10° to 60° C., after which stirring is continued for 30 minutes at 25° C. (cf. J. Chem. Soc. (C) (1968), 1593). The batch can then be worked up by stirring ice-water into the mixture and filtering off the precipitate which forms. Alternatively, it is possible to carry out the reaction by first taking the carboxylic acid halide and adding the anthranilic acid of the formula II.

Examples of suitable aromatic tertiary amines are pyridine, α, β- and γ-picoline, lutidine, quinoline and acridine.

The benzoxazine derivatives of the formula I may also be obtained by reacting an unsubstituted or substituted anthranilic acid of the formula II ##STR12## where R¹ and Y have the above meanings, or an alkali metal salt or alkaline earth metal salt of this anthranilic acid, with about the stoichiometric amount of carboxylic acid halide of the formula III ##STR13## where R² has the meanings given in claim 1 and Hal is halogen, in an inert organic solvent or in water, in the presence or absence of an acid acceptor, at from 0° to 60° C., to give a carboxylic acid amide of the formula IV ##STR14## where R¹, R² and Y have the above meanings, and then cyclizing this amide at from 30° to 150° C. in the presence of a dehydrating agent.

If 2,5-dimethylfuran-3-carboxylic acid chloride and anthranilic acid are used as the starting materials, the course of the reaction can be represented by the following equations: ##STR15##

Examples of suitable inert solvents are hydrocarbons, eg. naphtha, gasoline, toluene, pentane, hexane, cyclohexane and petroleum ether, halohydrocarbons, eg. methylene chloride, chloroform, carbon tetrachloride, 1,1- and 1,2-dichloroethane, 1,1,1- and 1,1,2-trichloroethane, chlorobenzene, o-, m- and p-dichlorobenzene and o-, m- and p-chlorotoluene, nitrohydrocarbons, eg. nitrobenzene, nitroethane and o-, m- and p-chloronitrobenzene, nitriles, eg. acetonitrile, butyronitrile and isobutyronitrile, ethers, eg. diethyl ether, di-n-propyl ether, tetrahydrofuran and dioxane, esters, eg. ethyl acetoacetate, ethyl acetate and isobutyl acetate, and amides, eg. formamide, methylformamide and dimethylformamide.

Any of the conventional acid-binding agents may be used as the acid acceptor. Amongst these, alkali metal hydroxides, alkali metal carbonates and tertiary organic bases are preferred. Specific examples of particularly suitable compounds are sodium hydroxide, sodium carbonate, sodium bicarbonate, triethylamine, pyridine, trimethylamine, α-, β- and γ-picoline, lutidine, N,N-dimethylaniline, N,N-dimethylcyclohexylamine, quinoline, tri-n-propylamine and tri-n-butylamine. Advantageously, the acid acceptor is employed in an amount equivalent to the carboxylic acid halide of the formula III.

Suitable dehydrating agents are symmetrical and mixed carboxylic acid anhydrides, eg. acetic anhydride, propionic anhydride, butyric anhydride, formic-acetic anhydride, formic-propionic anhydride and acetic-propionic anhydride, as well as dicyclohexylcarbodiimide and thionyl chloride. The cyclization is carried out with from 1 to 10 moles of dehydrating agent per mole of carboxylic acid amide of the formula IV.

The starting materials of the formulae II and III are employed in about the stoichiometric ratio, ie. to within ±10% of this ratio.

Advantageously, the process is carried out by adding the carboxylic acid halide of the formula III and the equivalent amount of acid acceptor from two separate feeds, at from 0° to 60° C., to an about equivalent amount of the anthranilic acid of the formula III, or a salt thereof, in an inert organic solvent or in water. The mixture is then stirred for 15 minutes at room temperature after which it is concentrated if necessary, acidified, whilst warm, with 5 N hydrochloric acid, cooled and filtered (J. Org. Chem. 2 (1944) 396), giving a N-acyl-2-aminobenzoic acid. This can be cyclized to the required 4H-3,1-benzoxazine in the presence of a 5- to 10-fold amount of acetic anhydride by stirring under reflux, with or without distillation of the acetic acid formed. To work up the mixture, excess acetic anhydride is removed on a rotary evaporator under reduced pressure and, if necessary, the product is purified by recrystallization. The carboxylic acid halide may also be introduced first into the receiver instead of the anthranilic acid.

Instead of using acetic anhydride, the cyclization can also be carried out with from 1 to 4 moles of dicyclohexylcarbodiimide or thionyl chloride per mole of N-acyl-2-aminobenzoic acid, at 30°-150° C.

In the case of reactive substituents R⁶, for example a carbamic acid ester group, it is advantageous first to prepare a nitro-substituted intermediate and then to react this, after reduction, with an acylating agent, for example as shown in the following equations: ##STR16##

However, it is also possible first to prepare a nitro-substituted 2-phenyl-3,1-benzoxazin-4-one, reduce this, convert the product into a reactive isocyanate by means of phosgene and then subject the latter to reactions with nucleophilic reactants, eg. amines, mercaptans or alcohols. ##STR17##

It is also possible to react an amino-substituted 2-phenyl-3,1-benzoxazin-4-one with an acylating reagent, eg. a carboxylic acid or sulfonic acid anhydride or chloride, in accordance with the following equations: ##STR18##

In the case of fluoroalkoxy-substituted or fluoroalkylmercapto-substituted 2-phenyl-3,1-benzoxazin-4-ones, it is advantageous to convert a fluoroalkoxy-substituted or fluoroalkylmercapto-substituted benzoic acid, by conventional methods, into the corresponding acid chloride (Houben-Weyl, Methoden der organischen Chemie, 8, 463 et seq., 4th edition, Georg-Thieme-Verlag, Stuttgart, 1952) and then convert the acid chloride, by means of an unsubstituted or substituted anthranilic acid, into the corresponding amide by a conventional method. The amide is then converted to the substituted 2-phenyl-3,1-benzoxazin-4-one by cyclization in the presence of a dehydrating agent.

To isolate the 4H-3,1-benzoxazine derivatives of the formula I from the reaction mixture, the latter may be treated with water, dilute alkali or dilute acid to separate out by-products, such as unconverted anthranilic acid, acid chloride or base hydrochloric, and may then be dried and concentrated. Where necessary, the end products can be purified by recrystallization or chromatography.

The following are examples of the preparation of carboxylic acid halides of the formula III to serve as intermediates for 4H-3,1-benzoxazin-4-ones:

3-Chloro-4-chlorodifluoromethoxybenzoyl fluoride

3-Chloro-4-methoxybenzoic acid is converted by means of thionyl chloride, by a conventional method, to 3-chloro-4-methoxybenzoyl chloride of boiling point 106° C./0.13 mbar and melting point 45°-50° C.

Chlorination of a mixture of 166 parts by weight of 3-chloro-4-methoxybenzoyl chloride and 10 parts by weight of phosphorus pentachloride for 7 hours at 195°-205° C. gives 208 parts by weight of 3-chloro-4-trichloromethoxybenzoyl chloride of boiling point 114° C./0.13 mbar and n_(D) ²⁵ =1.5780.

105 Parts by weight of 3-chloro-4-trichloromethoxybenzoyl chloride are introduced over 5 minutes into 92 parts by weight of antimony trifluoride at 90° C., whilst stirring, and the mixture is then stirred for 15 minutes at 110°-120° C. Distillation under reduced pressure gives 39.5 parts by weight of 3-chloro-4-chlorodifluoromethoxybenzoyl fluoride of boiling point 96°-105° C./13 mbar and n_(D) ²² =1.5185.

3-Chloro-4-trifluoromethoxybenzoyl fluoride

64 Parts by weight of 3-chloro-4-trichloromethoxybenzoyl chloride are introduced over 6 minutes into a mixture of 1.1 parts by weight of antimony pentachloride and 70 parts by weight of antimony trifluoride at 90° C., while stirring. The reaction mixture is stirred for 20 minutes at 190° C. and is then distilled under reduced pressure, giving 25 parts by weight of 3-chloro-4-trifluoromethoxybenzoyl fluoride, of n_(D) ²⁵ =1.4649.

3-Chlorodifluoromethoxy-4-chloro-benzoyl fluoride

A mixture of 86 parts by weight of 3-methoxy-4-chlorobenzoyl chloride and 5 parts by weight of phosphorus pentachloride is chlorinated for 7 hours at 195°-205° C., giving 112 parts by weight of 3-trichloromethoxy-4-chlorobenzoyl chloride of boiling point 92°-96° C./0.13 mbar.

69 Parts by weight of 3-trichloromethoxy-4-chlorobenzoyl chloride are introduced over 4 minutes into 60 parts by weight of antimony trifluoride at 90° C., whilst stirring, and the mixture is then stirred for 20 minutes at 110° C. Distillation gives 55 parts by weight of 3-chlorodifluoromethoxy-4-chlorobenzoyl fluoride of boiling point 88°-90° C./13 mbar and n_(D) ²² =1.5350.

3-Trifluoromethoxy-4-dichlorobenzoyl fluoride

30.8 Parts by weight of 3-trichloromethoxy-4-chlorobenzoyl chloride are introduced over 3 minutes into a mixture of 35.7 parts by weight of antimony trifluoride and 1 part by weight of antimony pentachloride at 90° C., whilst stirring, and the mixture is then stirred for 20 minutes at 190° C. Subsequent distillation gives 19 parts by weight of 3-trifluoromethoxy-4-chloro-benzoyl fluoride of boiling point 96°-103° C./39 mbar.

3-(1',1',2'-Trifluoro-2'-chloroethoxy)-benzoyl chloride

52.4 Parts by weight of chlorotrifluoroethylene are introduced, over 10 hours, into a mixture of 46.5 parts by weight of methyl 3-hydroxybenzoate and 9.5 parts by weight of potassium hydroxide powder in 50 parts by weight of acetone, refluxing at 45°-52° C. After concentrating the reaction mixture on a rotary evaporator under reduced pressure, the residue is taken up in methylene chloride and the solution is extracted with sodium bicarbonate solution, dried and evaporated, giving 69.5 parts by weight of methyl 3-(1',1',2'-trifluoro-2'-chloroethoxy)-benzoate of n_(D) ²⁵ =1.4710.

40 Parts by weight of methyl 3-(1',1',2'-trifluoro-2'-chloroethoxy)-benzoate, in a mixture of 8.4 parts by weight of potassium hydroxide, 100 parts by weight of water and 5 parts by weight of tetrahydrofuran, are stirred for 15 minutes at 95° C. The resulting solution is acidified with concentrated hydrochloric acid and the precipitate formed is filtered off and dried; 35 parts of 3-(1',1',2'-trifluoro-2'-chloroethoxy)benzoic acid of melting point 79°-85° C. are obtained.

35 Parts by weight of 3-(1',1',2'-trifluoro-2'-chloroethoxy)-benzoic acid are converted to 3-(1',1',2'-trifluoro-2'-chloroethoxy)-benzoyl chloride, of n_(D) ²² =1.4900 (IR: C═O 1,760 and 1,742 cm⁻¹) in a conventional manner by means of 20.2 parts by weight of thionyl chloride and 0.2 part by weight of pyridine as the catalyst. Yield: 34.5 parts by weight, corresponding to 92% of theory.

3,4-Difluorobenzoyl chloride

36 Parts by weight of 3,4-difluorobenzoic acid (J. org. Chem. 27 (1962), 2,923) are converted to the corresponding acid chloride, of boiling point 63°-66° C./10 mbar (IR: C═O 1,752 cm⁻¹) in a conventional manner by means of 59.5 parts by weight of thionyl chloride and 0.2 part by weight of pyridine. Yield: 25 parts by weight of 3,4-difluorobenzoyl chloride.

3-Chloro-4-fluorobenzoyl chloride

100 Parts by weight of 3-chloro-4-fluorobenzoic acid (J. Chem. Soc. 1693, 2784) are converted to the corresponding acid chloride in a conventional manner by means of 83.3 parts by weight of thionyl chloride and 0.2 part by weight of pyridine. Yield: 63.1 parts by weight of 3-chloro-4-fluorobenzoyl chloride, of boiling point 45°-47° C./0.13 mbar.

The Examples which follow illustrate the preparation of some 4H-3,1-benzoxazine derivatives. Parts by weight bear the same relation to parts by volume as that of the kilogram to the liter.

EXAMPLE 1 Preparation of 2-(m-methoxycarbamylphenyl)-3,1-benzoxazin-4-one

3-Nitrobenzoyl chloride and anthranilic acid are converted by a conventional method to 3-nitrobenzoylanthanilic acid, of melting point 242°-247° C. (J. Am. Chem. Soc. 33 (1911), 952).

56 parts by weight of the amide thus obtained, in a mixture of 400 parts by volume of absolute ethanol and 15 parts by weight of Raney nickel, are hydrogenated for 3 hours at 60° C. under a pressure of 100 bar. The reaction mixture is filtered, the filter residue is washed with ethanol, and the filtrates are concentrated under reduced pressure. The residue obtained is taken up in 3 N sodium hydroxide solution and the resulting solution is extracted once with ether and stirred into dilute hydrochloric acid. After filtering off the product, and drying it, 3-aminobenzoylanthranilic acid (melting point 260° C., with decomposition) is obtained.

41 parts by weight of the acid thus obtained and 17.1 parts by weight of triethylamine are dissolved in 700 parts by volume of 1,2-dichloroethane and 16.1 parts by weight of methyl chloroformate are added from a dropping funnel, at 25° C., whilst stirring. After stirring the mixture for 12 hours, the precipitate which has formed is filtered off, washed with water and dried, giving m-methoxycarbamyl-benzoylanthranilic acid of melting point 216°-220° C.

16 parts by weight of the compound thus obtained and 130 parts by volume of acetic anhydride are refluxed for 1 hour, whilst stirring. When the mixture has cooled, the precipitate is filtered off, washed with ether and dried, giving 13 parts by weight of 2-(m-methoxycarbamylphenyl)-3,1-benzoxazin-4-one of melting point 223°-226° C.; yield: 88% of theory.

EXAMPLE 2 Preparation of 2-(m-ethoxycarbamylphenyl)-3,1-benzoxazin-4-one

21 Parts by weight of 2-(m-nitrophenyl)-3,1-benzoxazin-4-one, in a mixture of 160 parts by volume of 1,4-dioxane and 2.5 parts by weight of 5% strength palladium on charcoal, are hydrogenated for 10 hours at 50° C. under a pressure of 20 bar. The catalyst is removed by filtration and the reaction mixture is concentrated under reduced pressure and then stirred with 50 parts by volume of 1 N sodium hydroxide solution, and the precipitated 2-(m-aminophenyl)-3,1-benzoxazin-4-one is washed with water and dried; melting point 150°-154° C.

40 Parts by weight of 2-(m-aminophenyl)-3,1-benzoxazin-4-one are suspended in 300 parts by volume of chlorobenzene and the suspension is treated with hydrogen chloride gas until saturated therewith, and then with phosgene gas for 4 hours at 110° C. The clear solution is concentrated under reduced pressure and the residue is then washed with ether and petroleum ether, giving 39 parts by weight of 2-(m-isocyanatophenyl)-3,1-benzoxazin-4-one of melting point 115°-121° C.

2.4 parts by weight of absolute ethanol and 1 drop of triethylamine as the catalyst are added to a solution of 13.2 parts by weight of 2-(m-isocyanatophenyl)-3,1-benzoxazin-4-one in 150 parts by volume of 1,2-dichloroethane at 25° C., whilst stirring. The reaction mixture is stirred for 2 hours at 50° C. and cooled, and the product is filtered off. After washing the latter with ether and petroleum ether, 2-(m-ethoxycarbamyl-phenyl)-3,1-benzoxazin-4-one is obtained in the form of colorless crystals of melting point 179°-183° C. Yield: 10.5 parts by weight, corresponding to 68% of theory.

EXAMPLE 3 Preparation of 2-(m-1',1',2',2'-tetrafluoroethoxyphenyl)-3,1-benzoxazin-4-one

39.4 parts by weight of thionyl chloride are added to a suspension of 65 parts by weight of m-(1,1,2,2-tetrafluoroethoxy)-benzoic acid in 500 parts by volume of 1,2-dichloroethane and the mixture is stirred for 3 hours under reflux. It is then concentrated under reduced pressure, and after filtering off a small amount of starting material which has precipitated, m-(1,1,2,2-tetrafluoroethoxy)-benzoyl chloride is obtained as a yellowish oil. The IR spectrum shows C═O bands at 1,770 and 1,748 cm⁻¹ and fluoroalkoxy bands at 1,225, 1,190 and 1,125 cm⁻¹.

25.7 Parts by weight of m-(1,1,2,2-tetrafluoroethoxy)-benzoyl chloride and 10.1 parts by weight of triethylamine are added from two separate feeds, over 15 minutes, to a stirred mixture of 13.7 parts by weight of anthranilic acid and 300 parts by volume of 1,2-dichloroethane, and stirring is continued for 12 hours at room temperature. The reaction mixture is extracted with 0.5 N hydrochloric acid and with water, dried over magnesium sulfate and concentrated under reduced pressure. After triturating the product in 0.5 N hydrochloric acid, filtering off and washing with water, m-(1,1,2,2-tetrafluoroethoxy)-benzoylanthranilic acid of melting point 159°-163° C. is obtained.

21 parts by weight of the product thus obtained are cyclized for 3 hours in 200 parts by volume of refluxing acetic anhydride, whilst stirring. The reaction mixture is then concentrated under reduced pressure, the residue is taken up in methylene chloride and the solution is chromatographed over neutral aluminum oxide. After concentrating the eluate, 16 parts by weight of 2-(m-1',1',2',2'-tetrafluoroethoxyphenyl)-3,1-benzoxazin-4-one of melting point 95°-98° C. are obtained.

EXAMPLE 4 Preparation of 2-(m-difluoromethoxy-phenyl)-3,1-benzoxazin-4-one

260 Parts by eight of chlorodifluoromethane are passed, over 1.5 hours, into a stirred mixture of 221 parts by weight of m-cresol, 412 parts by weight of sodium hydroxide, 600 parts by volume of 1,4-dioxane and 500 parts by volume of water, at 67°-70° C. After stirring for 45 minutes at 68° C., the reaction mixture is cooled, diluted with 1,000 parts by volume of water and extracted four times with 200 parts by volume of ether. After drying the ether phase, concentrating under reduced pressure and distilling, 172 parts by weight of m-tolyl difluoromethyl ether of boiling point 64°-67° C./24.7 mbar are obtained.

A mixture of 47.4 parts by weight of m-tolyl difluoromethyl ether, 77 parts by weight of magnesium sulfate, 134.3 parts by weight of potassium permanganate and 1,900 parts by volume of water is stirred for 3 hours at 50°-60° C. for 2 hours at 90° C. After destroying excess permanganate with ethanol, the solution is filtered whilst still hot and the filtrate is then acidified. The precipitate formed is taken up in methylene chloride and the extract is dried; after concentrating under reduced pressure, 3-difluoromethoxybenzoic acid of melting point 85°-87° C. is obtained.

The above acid can be converted by means of thionyl chloride, in a conventional manner, to 3-difluoromethoxybenzoyl chloride of n_(D) ²⁵ =1.5083.

25 parts by weight of 3-difluoromethoxybenzoyl chloride and 12.2 parts by weight of triethylamine are added over 15 minutes, from 2 separate feeds, to a stirred mixture of 16.6 parts by weight of anthranilic acid in 360 parts by weight of 1,2-dichloroethane at 25°-30° C. After stirring for 2 hours at 25° C., the reaction mixture is extracted with 0.5 N hydrochloric acid and with water. The organic phase is then extracted with four times 100 parts of 0.5 N sodium hydroxide solution, and the extracts are stirred into dilute hydrochloric acid. After filtration and drying, 30.4 parts by weight, corresponding to 82% of theory, of N-(3-difluoromethoxybenzoyl)-anthranilic acid of melting point 186°-191° C. are obtained. 8.33 Parts by weight of thionyl chloride are introduced into a stirred mixture of 18 parts by weight of N-(3-difluoromethoxybenzoyl)anthranilic acid in 250 parts by weight of 1,2-dichloroethane at 25° C.; the mixture is then stirred for 4 hours under reflux. When it has cooled, the reaction mixture is extracted with 100 parts by volume of ice-water and 100 parts by volume of 0.5 N sodium hydroxide solution and is chromatographed over neutral aluminum oxide. 12 parts by weight, corresponding to 71% of theory, of 2-(3'-difluoromethoxy-phenyl)-3,1-benzoxazin-4-one, of melting point 84°-87° C., are obtained.

EXAMPLE 5 Preparation of 2-(m-trifluoromethylsulfinyl-phenyl)-3,1-benzoxazin-4-one

8.85 Parts by weight of m-chloroperbenzoic acid in 150 parts of methylene chloride are added to a mixture of 16.2 parts of 2-(m-trifluoromethylmercapto-phenyl)-3,1-benzoxazin-4-one and 130 parts of methylene chloride at room temperature. The mixture is then stirred for a further 22 hours. The precipitate, which has formed is dissolved by adding 100 parts of methylene chloride and the solution obtained is extracted twice with 0.3 N sodium hydroxide solution and with water. It is then dried over magnesium sulfate and chromatographed over aluminum oxide, giving 12.4 parts of 2-(m-trifluoromethylsulfinyl-phenyl)-3,1-benzoxazin-4-one, of melting point 106°-108° C.

EXAMPLE 6 Preparation of 2-(m-trifluoromethylsulfonyl-phenyl)-3,1-benzoxazin-4-one

Following the method described in Example 5, but starting from 17.3 parts of m-chloroperbenzoic acid, 12 parts of 2-(m-trifluoromethylsulfonyl-phenyl)-3,1-benzoxazin-4-one, of melting point 96°-102° C., are obtained.

Using corresponding methods, the following 4-H-3,1-benzoxazine derivatives of the formula I can be prepared:

    __________________________________________________________________________      ##STR19##                                                                

    __________________________________________________________________________     R.sup.2           Y m.p. [°C.]                                                                        R.sup.2         Y m.p. [°C.]              __________________________________________________________________________      ##STR20##        O                                                             ##STR21##        O 120-123                                                                                   ##STR22##      S                                 ##STR23##        S                                                                                           ##STR24##      O 145-149                         ##STR25##        O                                                                                           ##STR26##      O 107-110                         ##STR27##        O 87-90                                                                                     ##STR28##      O                                 ##STR29##        O 94-95                                                                                     ##STR30##      O 108-112                         ##STR31##        O  98-102                                                                                   ##STR32##      S                                 ##STR33##        O                                                                                           ##STR34##      O                                 ##STR35##        O 82-86                                                                                     ##STR36##      O                                 ##STR37##        O                                                                                           ##STR38##      O 87-90                           ##STR39##        S                                                                                           ##STR40##      S                                 ##STR41##        O                                                                                           ##STR42##      O                                 ##STR43##        O 146-151                                                                                   ##STR44##      O                                 ##STR45##        S                                                                                           ##STR46##      S                                 ##STR47##        S                                                                                           ##STR48##      O                                 ##STR49##        S                                                                                           ##STR50##      O                                 ##STR51##        O                                                                                           ##STR52##      S                                 ##STR53##        O                                                                                           ##STR54##      O                                 ##STR55##        O 200-202                                                                                   ##STR56##      O                                 ##STR57##        O                                                                                           ##STR58##      O                                 ##STR59##        O                                                                                           ##STR60##      O                                 ##STR61##        O                                                                                           ##STR62##      O                                __________________________________________________________________________               Y          R.sup.2     m.p. [°C.]                             __________________________________________________________________________               O                                                                                          ##STR63##  130-134                                                 O                                                                                          ##STR64##                                                          S                                                                                          ##STR65##                                                          O                                                                                          ##STR66##  170-173                                                 O                                                                                          ##STR67##                                                          O                                                                                          ##STR68##                                                          O                                                                                          ##STR69##                                                          O                                                                                          ##STR70##  155-158                                                 O                                                                                          ##STR71##                                                          O                                                                                          ##STR72##  177-180                                                 O                                                                                          ##STR73##                                                          O                                                                                          ##STR74##                                                          O                                                                                          ##STR75##                                                          O                                                                                          ##STR76##  149-153                                                 O                                                                                          ##STR77##                                                          O                                                                                          ##STR78##  188-191                                                 O                                                                                          ##STR79##                                                          S                                                                                          ##STR80##                                                          O                                                                                          ##STR81##                                                          O                                                                                          ##STR82##                                                          O                                                                                          ##STR83##                                                          O                                                                                          ##STR84##  174-178                                                 O                                                                                          ##STR85##  147-150                                                 O                                                                                          ##STR86##  117-120                                                 O                                                                                          ##STR87##  152-155                                                 O                                                                                          ##STR88##                                                          O                                                                                          ##STR89##                                                          O                                                                                          ##STR90##  103-106                                                 O                                                                                          ##STR91##                                                          O                                                                                          ##STR92##                                                          O                                                                                          ##STR93##                                                          O                                                                                          ##STR94##                                                          O                                                                                          ##STR95##  108-111                                                 O                                                                                          ##STR96##                                                __________________________________________________________________________               O          R.sup.2     m.p. [°C.]                             __________________________________________________________________________               O                                                                                          ##STR97##                                                          S                                                                                          ##STR98##                                                          O                                                                                          ##STR99##                                                          O                                                                                          ##STR100##                                                         O                                                                                          ##STR101## 157-160                                                 S                                                                                          ##STR102##                                               __________________________________________________________________________     R.sup.2              Y m.p. [°C.]                                                                   R.sup.2             Y m.p. [°C.]            __________________________________________________________________________      ##STR103##          O                                                          ##STR104##          O 105-108                                                                              ##STR105##         O                               ##STR106##          S                                                                                      ##STR107##         O                               ##STR108##          O                                                                                      ##STR109##         O                               ##STR110##          O                                                                                      ##STR111##         O                               ##STR112##          O                                                                                      ##STR113##         S                               ##STR114##          O                                                                                      ##STR115##         O                               ##STR116##          O                                                                                      ##STR117##         O                               ##STR118##          O                                                                                      ##STR119##         O                                                           ##STR120##         O                               ##STR121##          O                                                                                      ##STR122##         S                               ##STR123##          O 86-89                                                                                ##STR124##         O 88-91                         ##STR125##          O                                                                                      ##STR126##         O                               ##STR127##          S                                                                                      ##STR128##         O                               ##STR129##          O                                                                                      ##STR130##         O                               ##STR131##          O                                                                                      ##STR132##         O                               ##STR133##          O                                                                                      ##STR134##         O                               ##STR135##          O                                                                                      ##STR136##         O                               ##STR137##          O                                                                                      ##STR138##         O                               ##STR139##          O                                                                                      ##STR140##         O                               ##STR141##          O                                                                                      ##STR142##         O                               ##STR143##          O                                                                                      ##STR144##         S                               ##STR145##          S                                                                                      ##STR146##         O                               ##STR147##          O                                                                                      ##STR148##         O                               ##STR149##          O                                                                                      ##STR150##         O                               ##STR151##          O                                                                                      ##STR152##         O                               ##STR153##          O                                                                                      ##STR154##         O                               ##STR155##          S                                                                                      ##STR156##         O                               ##STR157##          O                                                                                      ##STR158##         O                               ##STR159##          O                                                                                      ##STR160##         O                               ##STR161##          O                                                                                      ##STR162##         O                               ##STR163##          O                                                                                      ##STR164##         O                               ##STR165##          O                                                                                      ##STR166##         O                               ##STR167##          S                                                                                      ##STR168##         O                               ##STR169##          O                                                          ##STR170##          O                                                                                      ##STR171##         O 118-121                       ##STR172##          O                                                                                      ##STR173##         O n.sub.D.sup.25 =                                                               1.5669                        ##STR174##          O                                                                                      ##STR175##         S                               ##STR176##          O                                                                                      ##STR177##         O                               ##STR178##          O                                                                                      ##STR179##         O n.sub.D.sup.25 =                                                               1.5510                        ##STR180##          O                                                          ##STR181##          O                                                                                      ##STR182##         O                               ##STR183##          S                                                                                      ##STR184##         O                               ##STR185##          O                                                                                      ##STR186##                                         ##STR187##          O                                                                                      ##STR188##         O                               ##STR189##          O                                                                                      ##STR190##         O                               ##STR191##          O 153-157                                                                              ##STR192##         O                                                           ##STR193##         O                                                           ##STR194##         O                               ##STR195##          O                                                                                      ##STR196##         O                               ##STR197##          O 202-205                                                                              ##STR198##         O 170-173                       ##STR199##          S                                                                                      ##STR200##         O                               ##STR201##          O                                                                                      ##STR202##         O                               ##STR203##          O                                                                                      ##STR204##         O 202-204                       ##STR205##          O                                                                                      ##STR206##         O                               ##STR207##          S                                                                                      ##STR208##         O 198-202                       ##STR209##          O                                                                                      ##STR210##         O                               ##STR211##          O                                                                                      ##STR212##         O 93-96                         ##STR213##          O 114-116                                                                              ##STR214##         O                               ##STR215##          O                                                                                      ##STR216##         O                               ##STR217##          O 103-105                                                                              ##STR218##         O 114-117                       ##STR219##          O 79-81                                                   __________________________________________________________________________

    ______________________________________                                          ##STR220##                                                               

    ______________________________________                                         R.sup.1   Y      R.sup.2            m.p. [°C.]                          ______________________________________                                         Br        O      C.sub.6 H.sub.5                                               SCN       O      C.sub.6 H.sub.5                                               CN        O      C.sub.6 H.sub.5                                               Cl        O      C.sub.6 H.sub.5    153-155                                    Cl        S      C.sub.6 H.sub.5                                               F         O      C.sub.6 H.sub.5    157-161                                    CCl.sub.3 O      C.sub.6 H.sub.5                                               CF.sub.3  O      C.sub.6 H.sub.5                                               CF.sub.3  S      C.sub.6 H.sub.5                                               Cl        O                                                                                      ##STR221##        124-128                                     ##STR222##                                                                              O      C.sub.6 H.sub.5                                               OCH.sub.3 O      C.sub.6 H.sub.5                                               SCH.sub.3 O      C.sub.6 H.sub.5                                               SOCH.sub.3                                                                               O      C.sub.6 H.sub.5                                               SO.sub.2 CH.sub.3                                                                        O      C.sub.6 H.sub.5                                               NO.sub.2  O      C.sub.6 H.sub.5    180                                        SO.sub.2 OCH.sub.3                                                                       O      C.sub.6 H.sub.5                                               CH.sub.3  O                                                                                      ##STR223##        125-127                                    SCN       O                                                                                      ##STR224##                                                   Cl        O                                                                                      ##STR225##        137-138                                    SO.sub.2 N(CH.sub.3).sub.2                                                               O                                                                                      ##STR226##                                                   CH.sub.3  O      C.sub.6 H.sub.5    152-155                                    F         O                                                                                      ##STR227##         98-100                                    F         O                                                                                      ##STR228##        92-96                                      CO.sub.2 CH.sub.3                                                                        O      C.sub.6 H.sub.5                                               Cl        S                                                                                      ##STR229##                                                   Cl        O                                                                                      ##STR230##        140-143                                    ______________________________________                                         R.sup.1   O      R.sup.2            m.p. [°C.]                          ______________________________________                                         Cl        O                                                                                      ##STR231##                                                   F         O                                                                                      ##STR232##        205-208                                    Cl        O                                                                                      ##STR233##                                                   Cl        O                                                                                      ##STR234##                                                   Cl        O                                                                                      ##STR235##                                                   ______________________________________                                         R.sup.1   Y      R.sup.2            m.p. [°C.]                          ______________________________________                                         Cl        O                                                                                      ##STR236##                                                   F         O                                                                                      ##STR237##                                                   Cl        O                                                                                      ##STR238##                                                   F         O                                                                                      ##STR239##                                                   CH.sub.3  O                                                                                      ##STR240##                                                   CH.sub.3  O                                                                                      ##STR241##                                                   CH.sub.3  O                                                                                      ##STR242##                                                   CH.sub.3  O                                                                                      ##STR243##                                                   CH.sub.3  O                                                                                      ##STR244##                                                   CH.sub.3  O                                                                                      ##STR245##                                                   CH.sub.3  O                                                                                      ##STR246##                                                   CN        O                                                                                      ##STR247##                                                   CN        O                                                                                      ##STR248##                                                   F         O                                                                                      ##STR249##        93-97                                      Cl        O                                                                                      ##STR250##        125-129                                    F         O                                                                                      ##STR251##        102-104                                    Cl        O                                                                                      ##STR252##        112-116                                    Cl        O                                                                                      ##STR253##        115-116                                    NO.sub.2  O                                                                                      ##STR254##        154-152                                    Cl        O                                                                                      ##STR255##        168-171                                    Cl        O                                                                                      ##STR256##                                                   CN        O                                                                                      ##STR257##                                                   CN        O                                                                                      ##STR258##                                                   CN        O                                                                                      ##STR259##                                                   NO.sub.2  O                                                                                      ##STR260##                                                   NO.sub.2  O                                                                                      ##STR261##                                                   ______________________________________                                    

The active ingredients according to the invention may be applied for instance in the form of directly sprayable solutions, powders, suspensions (including high-percentage aqueous, oily or other suspensions), dispersions, emulsions, oil dispersions, pastes, dusts, broadcasting agents, or granules by spraying, atomizing, dusting, broadcasting or watering. The forms of application depend entirely on the purpose for which the agents are being used; in any case they should ensure as fine a distribution of active ingredient as possible.

For the preparation of solutions, emulsions, pastes and oil dispersions to be sprayed direct, mineral oil fractions of medium to high boiling point, such as kerosene or diesel oil, further coal-tar oils, and oils of vegetable or animal origin, aliphatic, cyclic and aromatic hydrocarbons such as benzene, toluene, xylene, paraffin, tetrahydronaphthalene, alkylated naphthalenes and their derivatives such as methanol, ethanol, propanol, butanol, chloroform, carbon tetrachloride, cyclohexanol, cyclohexanone, chlorobenzene, isophorone, etc., and strongly polar solvents such as dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, water, etc. are suitable.

Aqueous formulations may be prepared from emulsion concentrates, pastes, oil dispersions or wettable powders by adding water. To prepare emulsions, pastes and oil dispersions the ingredients as such or dissolved in an oil or solvent may be homogenized in water by means of wetting or dispersing agents, adherents or emulsifiers. Concentrates which are suitable for dilution with water may be prepared from active ingredient, wetting agent, adherent, emulsifying or dispersing agent and possibly solvent or oil.

Examples of surfactants are: alkali metal, alkaline earth metal and ammonium salts of ligninsulfonic acid, naphthalenesulfonic acids, phenolsulfonic acids, alkylaryl sulfonates, alkyl sulfates, and alkyl sulfonates, alkali metal and alkaline earth metal salts of dibutylnaphthalenesulfonic acid, lauryl ether sulfate, fatty alcohol sulfates, alkali metal and alkaline earth metal salts of fatty acids; salts of sulfated hexadecanols, heptadecanols, and octadecanols, salts of sulfated fatty alcohol glycol ethers, condensation products of sulfonated naphthalene and naphthalene derivatives with formaldehyde, condensation products of naphthalene or naphthalenesulfonic acids with phenol and formaldehyde, polyoxyethylene octylphenol ethers, ethoxylated isooctylphenol, ethoxylated octylphenol and ethoxylated nonylphenol, alkylphenol polyglycol ethers, tributylphenyl polyglycol ethers, alkylaryl polyether alcohols, isotridecyl alcohol, fatty alcohol ethylene oxide condensates, ethoxylated castor oil, polyoxyethylene alkyl ethers, ethoxylated polyoxypropylene, lauryl alcohol polyglycol ether acetal, sorbitol esters, lignin, sulfite waste liquors and methyl cellulose.

Powders, dusts and broadcasting agents may be prepared by mixing or grinding the active ingredients with a solid carrier.

Granules, e.g., coated, impregnated or homogeneous granules, may be prepared by bonding the active ingredients to solid carriers. Examples of solid carriers are mineral earths such as silicic acid, silica gels, silicates, talc, kaolin, Attaclay, limestone, lime, chalk, bole, loess, clay, dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate, magnesium oxide, ground plastics, fertilizers such as ammonium sulfate, ammonium phosphate, ammonium nitrate, and ureas, and vegetable products such as grain flours, bark meal, wood meal, and nutshell meal, cellulosic powders, etc.

The formulations contain from 0.1 to 95, and preferably 0.5 to 90, % by weight of active ingredient.

Examples of formulations are as follows.

I. 90 Parts by weight of the compound of Example 1 is mixed with 10 parts by weight of N-methyl-α-pyrrolidone. A mixture is obtained which is suitable for application in the form of very fine drops.

II. 20 Parts by weight of the compound of Example 2 is dissolved in a mixture consisting of 80 parts by weight of xylene, 10 parts by weight of the adduct of 8 to 10 moles of ethylene oxide with 1 mole of oleic acid-N-monoethanolamide, 5 parts by weight of the calcium salt of dodecylbenzenesulfonic acid, and 5 parts by weight of the adduct of 40 moles of ethylene oxide with 1 mole of castor oil. By pouring the solution into 100,000 parts by weight of water and uniformly distributing it therein, an aqueous dispersion is obtained containing 0.02% by weight of the active ingredient.

III. 20 Parts by weight of the compound of Example 3 is dissolved in a mixture consisting of 40 parts by weight of cyclohexanone, 30 parts by weight of isobutanol, 20 parts by weight of the adduct of 7 moles of ethylene oxide with 1 mole of isooctylphenol, and 10 parts by weight of the adduct of 40 moles of ethylene oxide with 1 mole of castor oil. By pouring the solution into 100,000 parts by weight of water and finely distributing it therein, an aqueous dispersion is obtained containing 0.02% by weight of the active ingredient.

IV. 20 Parts by weight of the compound of Example 4 is dissolved in a mixture consisting of 25 parts by weight of cyclohexanol, 65 parts by weight of a mineral oil fraction having a boiling point between 210° and 280° C., and 10 parts by weight of the adduct of 40 moles of ethylene oxide with 1 mole of castor oil. By pouring the solution into 100,000 parts by weight of water and uniformly distributing it therein, an aqueous dispersion is obtained containing 0.02% by weight of the active ingredient

V. 20 Parts by weight of the compound of Example 2 is well mixed with 3 parts by weight of the sodium salt of diisobutylnaphthalene-α-sulfonic acid, 17 parts by weight of the sodium salt of a lignin-sulfonic acid obtained from a sulfite waste liquor, and 60 parts by weight of powdered silica gel, and triturated in a hammer mill. By uniformly distributing the mixture in 20,000 parts by weight of water, a spray liquor is obtained containing 0.1% by weight of the active ingredient.

VI. 3 Parts by weight of the compound of Example 1 is intimately mixed with 97 parts by weight of particulate kaolin. A dust is obtained containing 3% by weight of the active ingredient.

VII. 30 Parts by weight of the compound of Example 2 is intimately mixed with a mixture consisting of 92 parts by weight of powdered silica gel and 8 parts by weight of paraffin oil which has been sprayed onto the surface of this silica gel. A formulation of the active ingredient is obtained having good adherence.

VIII. 20 Parts of the compound of Example 3 is intimately mixed with 2 parts of the calcium salt of dodecylbenzenesulfonic acid, 8 parts of a fatty alcohol polyglycol ether, 2 parts of the sodium salt of a phenolsulfonic acid-urea-formaldehyde condensate and 68 parts of a paraffinic mineral oil. A stable oily dispersion is obtained.

The influence of various representatives of 4H-3,1-benzoxazine derivatives of the formula I on the growth of unwanted plants is demonstrated in greenhouse experiments.

The vessels employed were plastic flowerpots having a volume of 300 cm³, and which were filled with a sandy loam containing about 1.5% humus. The seeds of the test plants (cf. Table 1) were sown shallow, and separately, according to species, or pregerminated young plants or cuttings were transplanted. Generally, the plants were grown to a height of 3 to 10 cm, depending on the growth shape, before being treated. The compounds were emulsified or suspended in water as vehicle, and sprayed through finely distributing nozzles onto the shoot parts of the plants and the soil not completely covered by plants. The pots were set up in the greenhouse--species from warmer areas at from 20° to 30° C., and species from moderate climates at 10° to 20° C. The experiments were run for from 2 to 4 weeks. During this period, the plants were tended and their reactions to the various treatments assessed. The scale used for assessment was 0 to 100, 0 denoting no damage or normal emergence, and 100 denoting nonemergence or complete destruction of at least the visible plant parts.

The plant species used in the experiments are listed in Table 1.

The results given in the tables below show that the 4H-3,1-benzoxazine derivatives of the formula I have a better herbicidal action than prior art herbicidal benzoxazines, and are well tolerated by a number of crop plants. The compounds according to the invention are predominantly applied after emergence of the unwanted plants, either on cropland or uncropped land.

If the crop plants tolerate the active ingredients less well, application techniques may be used in which the agents are sprayed from suitable equipment in such a manner that the leaves of sensitive crop plants are if possible not touched, and the agents reach the soil or the unwanted plants growing beneath the crop plants (post-directed, lay-bytreatment).

                  TABLE 1                                                          ______________________________________                                         List of plant names                                                            Botanical name Abbreviation in tables                                                                        Common name                                      ______________________________________                                         Acanthospermum hispidum                                                                       Acanthosp. hisp.                                                                              bristly starbur                                  Arachis hypogaea              peanuts                                                                        (groundnuts)                                     Avena sativa                  oats                                             Beta vulgaris  Beta vulg.     sugarbeets                                       Centaurea spp.                knapweed                                         Chenopodium album                                                                             Chenopod. album                                                                               lambsquarters                                                                  (goosefoot)                                      Chrysanthemum segetum                                                                         Chrysanth. segetum                                                                            corn marigold                                    Cyperus spp.                  nutsedge                                         Datura stramonium                                                                             Datura stram   Jimsonweed                                       Desmodium tortuosum                                                                           Desmod. tort.  Florida                                                                        beggarweed                                       Euphorbia geniculata                                                                          Euphorb. genic.                                                                               wild poinsettia                                  Glycine max                   soybeans                                         Galeopsis spp.                hemp-nettle                                      Gossypium hirsutum                                                                            Gossyp. hirs.  cotton                                           Hordeum vulgare               barley                                           Matricaria spp.                                                                               Matric. spp.   chamomile                                        Malva neglecta                common                                                                         mallow                                           Mercurialis annua                                                                             Mercurial annua                                                                               annual                                                                         mercury                                          Oryza sativa                  rice                                             Sesbania exaltata             hemp sesbania                                                                  (coffeeweed)                                     Solanum nigrum Solan nigr.    black                                                                          nightshade                                       Sorghum bicolor               sorghum                                          Triticum aestivum             wheat                                            Xanthium pensylvanicum                                                                        Xanthium pens. common                                                                         cocklebur                                        Zea mays                      Indian corn                                      ______________________________________                                    

                                      TABLE 2                                      __________________________________________________________________________     Selective herbicidal action of new compounds; postemergence treatment in       the greenhouse                                                                  ##STR262##                                                                                  Crop plants - damage in % at appln. rate                                       of 1.0 kg/ha                                                                   Hordeum                                                                             Oryza                                                                              Sorghum                                                                             Triticum  Index of herbicidal action               R.sup.1                                                                          R.sup.2     vulgare                                                                             sativa                                                                             bicolor                                                                             aestivum                                                                            Zea mays                                                                            at appln. rate of 0.5                    __________________________________________________________________________                                           kg/ha.sup.x                                 ##STR263## 0    2   0    10   17   87                                       H                                                                                 ##STR264## 0    0   0     0    9   90                                       H                                                                                 ##STR265## 0    5   30   23   18   58                                       __________________________________________________________________________      0 = damage                                                                     100 =  plants destroyed                                                        .sup.x calculated from average values obtained with the following plants:      Chenopodium album, Cyperus spp., Chrysanthemum segetum, Datura stramonium      Matricaria spp., Mercurialis annua, Sesbania exaltata and Solanum nigrum 

                                      TABLE 3                                      __________________________________________________________________________     Selective control of weeds in groundnuts and other crops; postemergence        treatment in the greenhouse                                                     ##STR266##                                                                                      Test plants and % damage                                                 Appln. rate                                                                          Arachis                                                                             Glycine                                                                            Oryza                                                                              Sorghum                                                                             Zea                                                                               Sesbania                                                                            Xanthium                           R.sup.1                                                                          R.sup.2   [kg/ha]                                                                               hypogaea                                                                           max sativa                                                                             bicolor                                                                             mays                                                                              exaltata                                                                            pensylvanicum                      __________________________________________________________________________     Cl                                                                                ##STR267##                                                                              1.0   0    0   5   0    0  82   100                                   ##STR268##                                                                              1.0   0    7   6   0    6  81    30                                __________________________________________________________________________      0 = no damage                                                                  100 = plants destroyed                                                   

                                      TABLE 4                                      __________________________________________________________________________     Selective control of important broadleaved weeds in soybeans;                  postemergence treatment in the greenhouse                                       ##STR269##                                                                                    Test plants and % damage                                                 Appln. rate                                                                          Glycine                                                                            Chenopod.                                                                            Datura                                                                             Euphorbia                                                                            Solanum                                                                             Xanthium                              R.sup.2   [kg/ha]                                                                               max                                                                               album stram.                                                                             geniculata                                                                           nigrum                                                                              pens.                                 __________________________________________________________________________      ##STR270##                                                                              0.5   12  99    100 92    100  100                                    ##STR271##                                                                              0.5    8  70    100 99    100  100                                    ##STR272##                                                                              0.5   21  89     87 17     97   90                                   __________________________________________________________________________      0 = no damage                                                                  100 = plants destroyed                                                   

                  TABLE 5                                                          ______________________________________                                         Selective control of Galeopsis spp; postemergence treatment                    in the greenhouse                                                               ##STR273##                                                                                    Test plants and % damage                                                       Appln. rate                                                                              Hordeum                                                                               Triticum                                                                              Galeopsis                              R.sup.1                                                                            R.sup.2     [kg/ha]   vulgare                                                                               aestivum                                                                              spp.                                   ______________________________________                                              ##STR274## 0.5 1.0   0 0    10 10  90 94                                  H                                                                                   ##STR275## 0.5 1.0   0 0    20 23  30 40                                  (prior art)                                                                    ______________________________________                                    

                  TABLE 6                                                          ______________________________________                                         Selective herbicidal action of 4H3,1-benzoxacine derivatives;                  postemergence treatment in the greenhouse                                       ##STR276##                                                                                        Test plants                                                                    and % damage                                                                  Appln. rate                                                                               Avena Centaurea                                  R.sup.1                                                                            R.sup.2        [kg/ha]    sativa                                                                               spp.                                       ______________________________________                                              ##STR277##    3.0         0    100                                        Cl                                                                                  ##STR278##    3.0         0    100                                        Cl                                                                                  ##STR279##    3.0         0    100                                        H                                                                                   ##STR280##    3.0        20     70                                        H                                                                                   ##STR281##    3.0        40    100                                        H                                                                                   ##STR282##    3.0        80     90                                        H                                                                                   ##STR283##    3.0         0    100                                        H                                                                                   ##STR284##    3.0        40     90                                        H                                                                                   ##STR285##    3.0        80    100                                        H                                                                                   ##STR286##    3.0         0     80                                        ______________________________________                                    

                                      TABLE 7                                      __________________________________________________________________________     Control of broadleaved weeds in cereals; postemergence treatment in the        greenhouse                                                                      ##STR287##                                                                              Test plants and % damage                                                 Appln. rate                                                                          Hordeum                                                                             Oryza                                                                              Triticum                                                                            Chenopod.                                                                            Chrysanth.                                                                           Matricaria                                                                           Mercurialis                          R.sup.1                                                                            [kg/ha]                                                                               vulgare                                                                            sativa                                                                             aestivum                                                                            album segetum                                                                              spp.  annua                                __________________________________________________________________________     F   1.0   0    0   0    90    100   99    98                                   Cl  1.0   0    6   7    40    50    75    58                                   H   1.0   0    0   0    80    10     0     0                                   (prior                                                                         art)                                                                           __________________________________________________________________________      0 = no damage                                                                  100 = plants destroyed                                                   

                                      TABLE 8                                      __________________________________________________________________________     Selective control of unwanted plants; postemergence treatment in the           greenhouse                                                                      ##STR288##                                                                                     Test plants and % damage                                                 Appln. rate                                                                          Zea                                                                               Chenop.                                                                             Desmod.                                                                             Euphorb.                                                                            Matric.                                                                            Mercurial.                                                                           Malva                                                                               Solanum                      R.sup.1                                                                          R.sup.6  [kg/ha]                                                                               mays                                                                             album                                                                               tort.                                                                               genic.                                                                              spp.                                                                               annua neglecta                                                                            nigrum                       __________________________________________________________________________     H OCF.sub.2 CF.sub.3                                                                      0.5   0  100  100  100  100 100   100  100                          F OCF.sub.2 CF.sub.2 H                                                                    0.5   3  100  100  100  100 100   100  100                          Cl                                                                               OCF.sub.3                                                                               1.0   9   67   92   84  85   45   100   88                          H OCF.sub.2 CFHCL                                                                         0.5   0   99  100   98  --   90   --    95                          __________________________________________________________________________       0 = no damage                                                                 100 = plants destroyed                                                   

                                      TABLE 9                                      __________________________________________________________________________     Control of unwanted plants in cotton; postemergence treatment in the           greenhouse                                                                      ##STR289##                                                                               Test plants and % damage                                                 Appln. rate                                                                          Gossyp.                                                                            Acanthosp.                                                                           Chenop.                                                                             Datura                                                                             Euphorb.                                                                            Solan.                                                                             Xanthium                                                                            Sesbania                           R.sup.6                                                                             [kg/ha]                                                                               hirs.                                                                             hisp. alb. stram.                                                                             gen. nigr.                                                                              pens.                                                                               exalt.                             __________________________________________________________________________     SO.sub.2 CF.sub.3                                                                   1.0    0  100   87   100 79   93  100  73                                 CF.sub.3                                                                            1.0   43  100   97    80 26   99   99  67                                 __________________________________________________________________________      0 = no damage                                                                  100 = plants destroyed                                                   

                  TABLE 10                                                         ______________________________________                                         Selective control of weeds in sugarbeets;                                      postemergence treatment in the greenhouse                                       ##STR290##                                                                                      Test plants and % damage                                                                       Cheno-                                                         Appln. rate                                                                              Beta  podium                                                                               Solanum                                R.sup.1                                                                            R.sup.2       kg/ha     vulg. album nigrum                                 ______________________________________                                              ##STR291##   2.0       10    85    100                                    H                                                                                   ##STR292##   2.0       8     88    --                                     Cl                                                                                  ##STR293##   1.0       3     67    100                                    F                                                                                   ##STR294##   1.0       0     100   100                                    Cl                                                                                  ##STR295##   1.0       0     85    100                                    ______________________________________                                          0 =  no damage                                                                 100 = plants destroyed                                                   

In view of the good tolerance by the crop plants and the many application methods possible, the agents according to the invention, or mixtures containing them, may be used not only on the crop plants listed in the tables, but also in a much larger range of crops for removing unwanted plants. The application rates vary from 0.1 to 15 kg/ha and more.

The following crop plants may be mentioned by way of example:

    ______________________________________                                         Botanical name      Common name                                                ______________________________________                                         Allium cepa         onions                                                     Ananas comosus      pineapples                                                 Arachis hypogaea    peanuts (groundnuts)                                       Asparagus officinalis                                                                              asparagus                                                  Avena sativa        oats                                                       Beta vulgaris spp. altissima                                                                       sugarbeets                                                 Beta vulgaris spp. rapa                                                                            fodder beets                                               Beta vulgaris spp. esculenta                                                                       table beets, red beets                                     Brassica napus var. napus                                                                          rape                                                       Brassica napus var. napobrassica                                               Brassica napus var. rapa                                                                           turnips                                                    Brassica rapa var. silvestris                                                  Camellia sinensis   tea plants                                                 Carthamus tinctorius                                                                               safflower                                                  Carya illinoinensis pecan trees                                                Citrus limon        lemons                                                     Citrus maxima       grapefruits                                                Citrus reticulata                                                              Citrus sinensis     orange trees                                               Coffea arabica (Coffea                                                                             coffee plants                                              canephora, Coffea liberica)                                                    Cucumis melo        melons                                                     Cucumis sativus     cucumbers                                                  Cynodon dactylon    Bermudagrass                                                                   in turf and lawns                                          Daucus carota       carrots                                                    Elais guineensis    oil palms                                                  Fragaria vesca      strawberries                                               Glycine max         soybeans                                                   Gossypium hirsutum  cotton                                                     (Gossypium arboreum                                                            Gossypium herbaceum                                                            Gossypium vitifolium)                                                          Helianthus annuus   sunflowers                                                 Helianthus tuberosus                                                           Hevea brasiliensis  rubber plants                                              Hordeum vulgare     barley                                                     Humulus lupulus     hops                                                       Ipomoea bataras     sweet potatoes                                             Juglans regia       walnut trees                                               Lactuca sativa      lettuce                                                    Lens culinaris      lentils                                                    Linum usitatissimum flax                                                       Lycopersicon lycopersicum                                                                          tomatoes                                                   Malus spp.          apple trees                                                Manihot esculenta   cassava                                                    Medicago sativa     alfalfa (lucerne)                                          Mentha piperita     peppermint                                                 Musa spp.           banana plants                                              Nicothiana tabacum  tobacco                                                    (N. rustica)                                                                   Olea europaea       olive trees                                                Oryza sativa        rice                                                       Panicum millaceum                                                              Phaseolus lunatus   limabeans                                                  Phaseolus mungo     mungbeans                                                  Phaseolus vulgaris  snapbeans, green beans,                                                        dry beans                                                  Pennisetum glaucum                                                             Petroselinum crispum                                                                               parsley                                                    ssp. tuberosum                                                                 Picea abies         Norway spruce                                              Abies alba          fir trees                                                  Pinus spp.          pine trees                                                 Pisum sativum       English peas                                               Prunus avium        cherry trees                                               Prunus domestica    plum trees                                                 Prunus dulcis       almond trees                                               Prunus persica      peach trees                                                Pyrus communis      pear trees                                                 Ribes sylvestre     redcurrents                                                Ribes uva-crispa                                                               Ricinus communis                                                               Saccharum officinarum                                                                              sugar cane                                                 Secale cereale      rye                                                        Sesamum indicum     sesame                                                     Solanum tuberosum   Irish potatoes                                             Sorghum bicolor (S. vulgare)                                                                       grain sorghum                                              Sorghum dochna                                                                 Spinacia oleracea   spinach                                                    Theobroma cacao     cacao plants                                               Trifolium pratense  red clover                                                 Triticum aestivum   wheat                                                      Vaccinium corymbosum                                                                               blueberries                                                Vaccinium vitis -idaea                                                                             cranberries                                                Vicia faba          tick beans                                                 Vigna sinensis (V. unguiculata)                                                                    cow peas                                                   Vitis vinifera      grapes                                                     Zea mays            Indian corn, sweet corn,                                                       maize                                                      ______________________________________                                    

The 4H-3,1-benzoxazine derivatives of the formula I may be mixed with each other, or with numerous representatives of other herbicidal or growth-regulating active ingredient groups, and applied in such combinations. These combinations extend the spectrum of action, and synergistic effects are sometimes achieved. Examples of compounds which may be admixed are diazines, benzothiadiazinones, 2,6-dinitroanilines, N-phenylcarbamates, thiolcarbamates, halocarboxylic acids, triazines, amides, ureas, diphenyl ethers, triazinones, uracils, benzofuran derivatives, etc. A number of active ingredients which, together with the new compounds, give mixtures useful for widely varying applications are listed below by way of example.

    ______________________________________                                          ##STR296##                                                                    R                 R.sup.1     R.sup.2                                          ______________________________________                                          ##STR297##       NH.sub.2    Cl                                                ##STR298##       NH.sub.2    Br                                                ##STR299##       OCH.sub.3   OCH.sub.3                                         ##STR300##       N(CH.sub.3).sub.2                                                                          Cl                                                ##STR301##       OCH.sub.3   OCH.sub.3                                         ##STR302##       NH.sub.2    Cl                                                ##STR303##       N(CH.sub.3).sub.2                                                                          Cl                                                ##STR304##       NHCH.sub.3  Cl                                                ##STR305##       OCH.sub.3   Cl                                                ##STR306##       NH.sub.2    Br                                                ##STR307##       OCH.sub.3   OCH.sub.3                                         ##STR308##       NHCH.sub.3  Cl                                               ______________________________________                                    

    ______________________________________                                          ##STR309##                                                                    R             R.sup.1 R.sup.2   R.sup.3                                        ______________________________________                                         H             i-C.sub.3 H.sub.7                                                                      H         H (salts)                                      H             i-C.sub.3 H.sub.7                                                                      H         CH.sub.3 (salts)                               H             i-C.sub.3 H.sub.7                                                                      H         Cl (salts)                                     CH.sub.2OCH.sub.3                                                                            i-C.sub.3 H.sub.7                                                                      H         H                                              H             i-C.sub.3 H.sub.7                                                                      H         F (salts)                                      CH.sub.2OCH.sub.3                                                                            i-C.sub.3 H.sub.7                                                                      H         Cl                                             CH.sub.2OCH.sub.3                                                                            i-C.sub.3 H.sub.7                                                                      H         F                                              CN            i-C.sub.3 H.sub.7                                                                      H         Cl                                             ______________________________________                                    

    ______________________________________                                          ##STR310##                                                                    R     R.sup.1   R.sup.2 R.sup.3     R.sup.4                                    ______________________________________                                         H     H.sub.3 CSO.sub.2                                                                        H       n-C.sub.3 H.sub.7                                                                          n-C.sub.3 H.sub.7                          H     F.sub.3 C H       C.sub.2 H.sub.5                                                                            C.sub.4 H.sub.9                            H     F.sub.3 C H       n-C.sub.3 H.sub.7                                                                          n-C.sub.3 H.sub.7                          H     F.sub.3 C H       CH.sub.2CH.sub.2 Cl                                                                        n-C.sub.3 H.sub.7                          H     tert-C.sub.4 H.sub.9                                                                     H       sec-C.sub.4 H.sub.9                                                                        sec-C.sub.4 H.sub.9                        H     SO.sub.2 NH.sub.2                                                                        H       n-C.sub.3 H.sub.7                                                                          n-C.sub.3 H.sub.7                          H     F.sub.3 C H       n-C.sub.3 H.sub.7                                                                           ##STR311##                                H.sub.3 C                                                                            H.sub.3 C H       H           sec-C.sub.4 H.sub.9                        H.sub.3 C                                                                            H.sub.3 C H       H           CH(C.sub.2 H.sub.5).sub.2                  H     F.sub.3 C NH.sub.2                                                                               n-C.sub.3 H.sub.7                                                                          n-C.sub. 3 H.sub.7                         H     H.sub.3 C H       n-C.sub.3 H.sub.7                                                                          n-C.sub.3 H.sub.7                          H     i-C.sub.3 H.sub.7                                                                        H       n-C.sub.3 H.sub.7                                                                          n-C.sub.3 H.sub.7                          ______________________________________                                    

    ______________________________________                                          ##STR312##                                                                    R              R.sup.1 R.sup.2                                                 ______________________________________                                          ##STR313##    H       i-C.sub.3 H.sub.7                                       CH.sub.3       H                                                                                       ##STR314##                                              ##STR315##    H                                                                                       ##STR316##                                              ##STR317##    H       CH.sub.2CCH.sub.2 Cl                                     ##STR318##    H       i-C.sub.3 H.sub.7                                        ##STR319##    H                                                                                       ##STR320##                                              ##STR321##    H       CH.sub.3                                                 ##STR322##    H       CH.sub. 3                                               CH.sub.3       H                                                                                       ##STR323##                                              ##STR324##    H                                                                                       ##STR325##                                             ______________________________________                                    

    ______________________________________                                          ##STR326##                                                                    R                 R.sup.1                                                                               R.sup.2                                               ______________________________________                                          ##STR327##       H      CH.sub.3                                               ##STR328##       H      C.sub.2 H.sub.5                                        ##STR329##       H      C.sub.2 H.sub.5                                        ##STR330##       CH.sub.3                                                                              CH.sub.3                                               ##STR331##       H      CH.sub.3                                               ##STR332##       H      C.sub.2 H.sub.5                                        ##STR333##       H      C.sub.2 H.sub.5                                        ##STR334##       H      CH.sub.3                                               ##STR335##       H      CH.sub.3                                               ##STR336##                                                                    ______________________________________                                    

    ______________________________________                                          ##STR337##                                                                    R            R.sup.1   R.sup.2                                                 ______________________________________                                         i-C.sub.3 H.sub.7                                                                           i-C.sub.3 H.sub.7                                                                        CH.sub.2CClCCl.sub.2                                    i-C.sub.3 H.sub.7                                                                           i-C.sub.3 H.sub.7                                                                        CH.sub.2CClCHCl                                         n-C.sub.3 H.sub.7                                                                           n-C.sub.3 H.sub.7                                                                        C.sub.2 H.sub.5                                          ##STR338##  C.sub.2 H.sub.5                                                                          C.sub.2 H.sub.5                                         sec-C.sub.4 H.sub.9                                                                         sec-C.sub.4 H.sub.9                                                                      C.sub.2 H.sub.5                                         n-C.sub.3 H.sub.7                                                                           n-C.sub.3 H.sub.7                                                                        n-C.sub.3 H.sub.7                                       C.sub.2 H.sub.5                                                                             C.sub.2 H.sub.5                                                                           ##STR339##                                             sec-C.sub.4 H.sub.9                                                                         sec-C.sub.4 H.sub.9                                                                       ##STR340##                                              ##STR341##  C.sub.2 H.sub.5                                                                          C.sub.2 H.sub.5                                         i-C.sub.3 H.sub.7                                                                           i-C.sub.3 H.sub.7                                                                         ##STR342##                                             i-C.sub.3 H.sub.7                                                                           i-C.sub.3 H.sub.7                                                                         ##STR343##                                             ______________________________________                                          ##STR344##                                                                    ______________________________________                                         CH.sub.2CClCHCl                                                                CH.sub.2CClCCl.sub.2                                                            ##STR345##                                                                    ______________________________________                                    

    ______________________________________                                          ##STR346##                                                                    R                 X     Y      R.sup.1                                         ______________________________________                                         CH.sub.3          Cl    Cl     Na                                               ##STR347##       Cl    H      CH.sub.3                                         ##STR348##       H     H      H (salts)                                       Cl                Cl    Cl     Na                                               ##STR349##       H     CH.sub.3                                                                              CH.sub.3                                         ##STR350##       H     CH.sub.3                                                                              C.sub.2 H.sub.5                                 C.sub.2 H.sub.5   Cl    Cl     Na                                               ##STR351##       H     CH.sub.3                                                                              i-C.sub.3 H.sub.7                                ##STR352##       H     CH.sub.3                                                                              CH.sub.3                                         ##STR353##       H     CH.sub.3                                                                              CH.sub.2CH(CH.sub.3).sub.2                       ##STR354##       H     CH.sub.3                                                                              Na                                               ##STR355##       H     CH.sub.3                                                                              Na                                               ##STR356##       H     CH.sub.3                                                                              CH.sub.3                                        ______________________________________                                    

    ______________________________________                                          ##STR357##                                                                    R     R.sup.1    X       R.sup.2                                                                              R.sup.3                                         ______________________________________                                         H     tert-C.sub.4 H.sub.9                                                                      SCH.sub.3                                                                              H     C.sub.2 H.sub.5                                 H     C.sub.2 H.sub.5                                                                           SCH.sub.3                                                                              H     C.sub.2 H.sub.5                                 H     i-C.sub.3 H.sub.7                                                                         SCH.sub.3                                                                              H     C.sub.2 H.sub.5                                 H     CH.sub.3   SCH.sub.3                                                                              H     i-C.sub.3 H.sub.7                               H     i-C.sub.3 H.sub.7                                                                         Cl      H     C.sub.2 H.sub.5                                 H     i-C.sub.3 H.sub.7                                                                         Cl      H                                                                                     ##STR358##                                     H     C.sub.2 H.sub.5                                                                           Cl      H     C.sub.2 H.sub.5                                 H     C.sub.2 H.sub.5                                                                           Cl      H                                                                                     ##STR359##                                     H     i-C.sub.3 H.sub.7                                                                         Cl      H     i-C.sub.3 H.sub.7                               H     i-C.sub.3 H.sub.7                                                                         OCH.sub.3                                                                              H     i-C.sub.3 H.sub.7                                      ##STR360##                                                                               Cl      H                                                                                     ##STR361##                                     H     C.sub.2 H.sub.5                                                                           Cl      H                                                                                     ##STR362##                                     H     C.sub.2 H.sub.5                                                                           Cl      H                                                                                     ##STR363##                                     ______________________________________                                    

    __________________________________________________________________________      ##STR364##                                                                    R           R.sup.1        R.sup.2                                             __________________________________________________________________________     CH.sub.3    CH.sub.3       CH(C.sub.6 H.sub.5).sub.2                            ##STR365## H                                                                                              ##STR366##                                          ##STR367## H                                                                                              ##STR368##                                          ##STR369## H              C.sub.2 H.sub.5                                      ##STR370## H              C.sub.2 H.sub.5                                      ##STR371## H                                                                                              ##STR372##                                          ##STR373##                                                                                 ##STR374##    CH.sub.2 Cl                                          ##STR375##                                                                                 ##STR376##    CH.sub.2 Cl                                          ##STR377## CH.sub.2OCH.sub.3                                                                             CH.sub.2 Cl                                          ##STR378##                                                                                 ##STR379##    CH.sub.2 Cl                                          ##STR380## i-C.sub.3 H.sub.7                                                                             CH.sub.2 Cl                                          ##STR381## CH.sub.2OCH.sub.2CH(CH.sub.3).sub.2                                                           CH.sub.2 Cl                                          ##STR382## CH.sub.2On-C.sub.4 H.sub.9                                                                    CH.sub.2 Cl                                          ##STR383## CH.sub.2OC.sub.2 H.sub.5                                                                      CH.sub.2 Cl                                          ##STR384##                                                                                 ##STR385##    CH.sub.2 Cl                                          ##STR386## CH.sub.2CH.sub.2OCH.sub.3                                                                     CH.sub.2 Cl                                          ##STR387##                                                                                 ##STR388##    CH.sub.2 Cl                                          ##STR389##                                                                                 ##STR390##    CH.sub.2 Cl                                          ##STR391##                                                                                 ##STR392##    CH.sub.2 Cl                                          ##STR393##                                                                                 ##STR394##    CH.sub.2 Cl                                         CH.sub.3    CH.sub.3                                                                                       ##STR395##                                         C.sub.2 H.sub.5                                                                            C.sub.2 H.sub.5                                                                                ##STR396##                                         CH.sub.2CHCH.sub.2                                                                         CH.sub.2CHCH.sub.2                                                                            CH.sub.2 Cl                                          ##STR397##                                                                                 ##STR398##    CH.sub.2 Cl                                          ##STR399##                                                                                 ##STR400##    CH.sub.2 Cl                                          ##STR401## H                                                                                              ##STR402##                                          ##STR403## H              CH.sub.3                                             ##STR404## H              CH.sub.3                                            __________________________________________________________________________

    ______________________________________                                          ##STR405##                                                                    X              Y           R                                                   ______________________________________                                         Br             Br          H (salts)                                           I              I           H (salts)                                           Br             Br                                                                                          ##STR406##                                          ##STR407##            salts, esters                                            ##STR408##            salts, esters                                           ______________________________________                                    

    ______________________________________                                          ##STR409##                                                                    R              R.sup.1                                                                               R.sup.2   R.sup.3                                        ______________________________________                                          ##STR410##    H      CH.sub.3  CH.sub.3                                        ##STR411##    H      CH.sub.3  CH.sub.3                                        ##STR412##    H      CH.sub.3  CH.sub.3                                        ##STR413##    H      CH.sub.3  H                                               ##STR414##    CH.sub.3                                                                              CH.sub.3  H                                               ##STR415##    H      CH.sub.3  CH.sub.3                                        ##STR416##    H      CH.sub.3  CH.sub.3                                        ##STR417##    H                                                                                      ##STR418##                                                                              H                                               ##STR419##    H      CH.sub.3  CH.sub.3                                        ##STR420##    H      CH.sub.3                                                                                  ##STR421##                                     ##STR422##    H      CH.sub.3  OCH.sub.3                                       ##STR423##    H      CH.sub.3  CH.sub.3                                        ##STR424##    H                                                                                      ##STR425##                                                                              H                                               ##STR426##    H      CH.sub.3  OCH.sub.3                                       ##STR427##    H      CH.sub.3  CH.sub.3                                        ##STR428##    H      CH.sub.3  CH.sub.3                                        ##STR429##    H      CH.sub.3  CH.sub.3                                        ##STR430##    H      CH.sub.3  CH.sub.3                                        ##STR431##    H      CH.sub.3  OCH.sub.3                                       ##STR432##    H      CH.sub.3  OCH.sub.3                                       ##STR433##    H      CH.sub.3  H                                               ##STR434##    CH.sub.3                                                                              CH.sub.3  H                                               ##STR435##    CH.sub.3                                                                              CH.sub.3  H                                               ##STR436##    H      C.sub.2 H.sub.5                                                                          C.sub.2 H.sub.5                                 ##STR437##    H      CH.sub.3  CH.sub.3                                        ##STR438##    H      CH.sub.3  OCH.sub.3                                       ##STR439##    H      CH.sub.3  CH.sub.3                                        ##STR440##                                                                    ______________________________________                                    

    ______________________________________                                          ##STR441##                                                                    R          R.sup.1   R.sup.2  R.sup.3                                          ______________________________________                                         Cl         Cl        Cl       H                                                F          Cl        Cl       H                                                NO.sub.2   CF.sub.3  H        H                                                Cl         CF.sub.3  H        COOH (salts)                                     Cl         Cl        H        H                                                Cl         Cl        H        OCH.sub.3                                        Cl         Cl        H                                                                                        ##STR442##                                      H          CF.sub.3  Cl       H                                                H          CF.sub.3  Cl       OC.sub.2 H.sub.5                                 ______________________________________                                    

    ______________________________________                                          ##STR443##                                                                    R            R.sup.1           R.sup.2                                         ______________________________________                                         tert-C.sub.4 H.sub.9                                                                        NH.sub.2          SCH.sub.3                                       tert-C.sub.4 H.sub.9                                                                        NCHCH(CH.sub.3).sub.2                                                                            SCH.sub.3                                        ##STR444##  NH.sub.2          CH.sub.3                                        ______________________________________                                    

    ______________________________________                                          ##STR445##                                                                    R          R.sup.1   R.sup.2  R.sup.3                                          ______________________________________                                         H          CH.sub.3  Br                                                                                       ##STR446##                                      H          CH.sub.3  Br       i-C.sub.3 H.sub.7                                H          CH.sub.3  Cl       tert-C.sub.4 H.sub.9                             H          CH.sub.3  Cl                                                                                       ##STR447##                                       ##STR448##                                                                    ______________________________________                                    

    ______________________________________                                          ##STR449##                                                                    R           R.sup.1    R.sup.2  R.sup.3                                        ______________________________________                                          ##STR450## sec-C.sub.4 H.sub.9                                                                       H        H                                              H           CH.sub.3   H        H (salts, esters)                              H           sec-C.sub.4 H.sub.9                                                                       H        H (salts, esters)                               ##STR451## tert-C.sub.4 H.sub.9                                                                      H        H                                               ##STR452## tert-C.sub.4 H.sub.9                                                                      H        CH.sub.3                                       H           i-C.sub.3 H.sub.7                                                                         CH.sub.3 H (salts, esters)                              H           tert-C.sub.4 H.sub.9                                                                      H        H (salts)                                      ______________________________________                                    

    ______________________________________                                          ##STR453##                                                                    X               Y           R                                                  ______________________________________                                         CF.sub.3        H           CH.sub.3                                           H               F           CH.sub.3                                            ##STR454##                                                                    ______________________________________                                    

    ______________________________________                                          ##STR455##                                                                    R                      R.sup.1                                                 ______________________________________                                         CH.sub.3               C.sub.2 H.sub.5                                          ##STR456##            C.sub.2 H.sub.5                                          ##STR457##            C.sub.2 H.sub.5                                         ______________________________________                                    

    ______________________________________                                          ##STR458##                                                                    R                         R.sup.1                                              ______________________________________                                          ##STR459##               CH.sub.3                                              ##STR460##               CH.sub.3                                              ##STR461##               CH.sub.3                                             ______________________________________                                    

    ______________________________________                                          ##STR462##                                                                    R        R.sup.1  R.sup.2  X                                                   ______________________________________                                         CH.sub.3 CH.sub.3 H                                                                                        ##STR463##                                         CH.sub.3 CH.sub.3 Br       CH.sub.3 OSO.sub.2 O                                CH.sub.3 CH.sub.3 CH.sub.3 CH.sub.3 OSO.sub.2O                                 CH.sub.3 CH.sub.3 CH.sub.3 CF.sub.3SO.sub.2                                     ##STR464##                                                                     ##STR465##                                                                     ##STR466##                                                                     ##STR467##                                                                     ##STR468##                                                                     ##STR469##                                                                     ##STR470##                                                                     ##STR471##                                                                     ##STR472##                                                                     ##STR473##                                                                     ##STR474##                                                                     ##STR475##                                                                     ##STR476##                                                                    ______________________________________                                    

    ______________________________________                                          ##STR477##                                                                                 R                                                                 ______________________________________                                                      CN                                                                             CSNH.sub.2                                                        ______________________________________                                    

    ______________________________________                                          ##STR478##                                                                    R       R.sup.1 R.sup.2  R.sup.3 R.sup.4                                       ______________________________________                                         H       Cl      NH.sub.2 Cl      (salts, esters,                                                                amides)                                       Cl      Cl      H        Cl      Na                                            H       I       I        I       H                                             Cl      H       Cl       OCH.sub.3                                                                              H                                             Cl      Cl      H        Cl      (CH.sub.3).sub.2 NH.sub.2                     ______________________________________                                    

    ______________________________________                                          ##STR479##                                                                    R              R.sup.1  R.sup.2                                                ______________________________________                                          ##STR480##    CH.sub.3 H (salts, esters, amides)                               ##STR481##    H        H (salts, esters, amides)                               ##STR482##    H        H (salts, esters, amides)                               ##STR483##    H        H (salts, esters, amides)                               ##STR484##    CH.sub.3 H (salts, esters, amides)                               ##STR485##    CH.sub.3 H (salts, esters, amides)                               ##STR486##                                                                     ##STR487##          (salts, esters, amides)                                    ##STR488##          (salts, esters, amides)                                    ##STR489##          (salts, esters, amides)                                   ______________________________________                                    

    ______________________________________                                          ##STR490##                                                                    R               R.sup.1     R.sup.2                                            ______________________________________                                         OH              CH.sub.3    Na                                                 CH.sub.3        CH.sub.3    Na                                                 CH.sub.3        CH.sub.3    OH                                                 ONa             CH.sub.3    Na                                                 ______________________________________                                    

    ______________________________________                                          ##STR491##                                                                    R             R.sup.1         R.sup.2                                          ______________________________________                                          ##STR492##   CH.sub.2OC.sub.2 H.sub.5                                                                       CH.sub.3                                          ##STR493##   i-C.sub.3 H.sub.7OCH.sub.2                                                                     CH.sub.3                                          ##STR494##   CH.sub.2OC.sub.2 H.sub.5                                                                       CH.sub.3                                          ##STR495##   i-C.sub.3 H.sub.7                                                                              NHCH.sub.3                                        ##STR496##                                                                     ##STR497##                                                                     ##STR498##                                                                     ##STR499##                                                                     ##STR500##                                                                     ##STR501##                                                                     ##STR502##                                                                     ##STR503##                                                                     ##STR504##                                                                     ##STR505##                                                                     ##STR506##                                                                     ##STR507##                                                                     ##STR508##                                                                     ##STR509##                                                                     ##STR510##                                                                     ##STR511##                                                                     ##STR512##                                                                    NH.sub.4 SCN                                                                    ##STR513##                                                                     ##STR514##                                                                     ##STR515##                                                                     ##STR516##                                                                     ##STR517##                                                                     ##STR518##                                                                     ##STR519##                                                                     ##STR520##                                                                     ##STR521##                                                                     ##STR522##                                                                     ##STR523##                                                                     ##STR524##                                                                     ##STR525##                                                                    ______________________________________                                    

It may also be useful to apply the new compounds, either alone or in combination with other herbicides, in admixture with other crop protection agents, e.g., agents for combating pests or phytopathogenic fungi or bacteria. The compounds may also be mixed with solutions of mineral matters used to remedy nutritional or trace element deficiencies. It may also be advantaeous to apply the compounds according to the invention (either on their own or in possible combinations) in admixture with solid or liquid mineral fertilizers. 

We claim:
 1. 4H-3,1-Benzoxazine derivatives of the formula ##STR526## where Y is oxygen or sulfur, .Iadd.R² is .Iaddend.Ar(R⁶)_(n), Ar denoting phenyl, R⁶ denoting haloalkoxy or haloalkylmercapto, each of 1 to 4 carbon atoms, and n being 1 or
 2. 2. 2-(p-Trifluoromethoxy-phenyl)-3,1-benzoxazin-4-one.
 3. 2-(m-Trifluoromethoxy-phenyl)-3,1-benzoxazin-4-one.
 4. 2-(m-1',1',2',2'-Tetrafluoroethoxy-phenyl)-3,1-benzoxazin-4-one.
 5. A herbicide comprising a solid and/or liquid inert carrier and a 4H-3,1-benzoxazine derivative of the formula I as claimed in claim
 1. 6. A process for combating unwanted plant growth, wherein the plants or the soil are treated with a herbicidally effective amount of a 4H-3,1-benzoxazine derivative of the formula I as claimed in claim
 1. 7. A compound as set forth in claim 1 wherein n is
 1. 8. 2-(m-chlorodifluoromethoxy-phenyl)-3,1-benzoxazin-4-one.
 9. 2-(m-trifluoromethylmercapto-phenyl)-3,1-benzoxazin-4-one.
 10. 2-(m-chlorodifluoromethylmercapto-phenyl)-3,1-benzoxazin-4-one. .Iadd.
 11. 4H-3,1-Benzoxazine derivatives of the formula ##STR527## where R¹ is fluorine or chlorine, Y is oxygen or sulfur and R² is phenyl. .Iaddend. .Iadd.
 12. A 4H-3,1-Benzoxazine derivative as in claim 1, wherein R¹ is fluorine and Y is oxygen. .Iaddend. .Iadd.13. A 4H-3,1-Benzoxazine derivative as in claim 1, wherein R¹ is chlorine and Y is oxygen. .Iaddend. 